There are finally some really good utilities coming out for EVE on the Mac. One of them is a widget that runs on the dashboard and can even be run on the iPhone. Here is a picture of what it looks like in action, and the widget can be downloaded from the EVE Online forums.
There also seems to be a program in the works that will emulate all the things that EVEMon does, but it will be completely Cocoa based. The program is called Skill Monitor Cocoa. It still needs a lot of work, but the screenshots look very promising and it is somewhat functional albeit a little buggy at times.